Power plant



Sept. 26, 1933. R WW2 1,927,970

POWER PLAN T Filed Oct. 31, 1929 5 Sheets-Sheet 1 Sept. 26, 1933. RWINTZER 1,927,970

POWER PLANT Filed OCh. 31, 1929 5 Sheets-Sheet 2 m Snow ate! MOW IX/Mumilk K0144421 3 R. WINTZER Sept. 26, 1933.

POWER PLANT Filed Oct. 51, 1929 5 Sheets-Sheet 4 3 mm mm I I ll v|| A 1mum EMQW Wm 02/ Sept. 26, 1933. R. WINTZER 1,927,970

POWER PLANT Filed Oct. 31, 1929 5 Sheets-Sheet 5 Patented Sept. 26, 19331,927,970 POWER PLANT Rudolf Wintzer, Milwaukee, Wis., assignor 'toNortlberg; Manufacturing Company, Milwaukee, Wis., a corporation ofWisconsi I Application October 31, 1929. Serial No. 403,852

18 Claims invention relates to power plants, and particularly to acontrolling mechanism-for a; power plant comprising: a prime: mover suchas an internal combustion engine, for example, a Diesel engine, and apneumatic; transmission.

In. the following description the enginewill be referred to as a Dieselengine, because,'.under present conditions that type. of engine will beused in most installations in which the advantages of the presentinvention would be desired,

For lack of a. better name the transmission will be referred to. as apneumatic transmission, without, however; any intention to limit theinvention to the use of air as contradistinguished from othercompressible gases. Itis contemplated that this pneumatic. transmissionwill be of what is colloquially termed the dense air type, by which ismeant that the 'expansible gas used (usually air) flows in a closedcycle between the compressor and an expansion engine and is at all timesat a pressure higher than atmospheric.

By adopting the dense air cycle, using a high. pressure of say 280pounds gage, and a low or return pressure of say 80 pounds gage, theexpansion ratio is kept-within reasonable limits, thus avoidingCI-lfiClllTLlBS incident to frosting and the like, Y a

No. novelty for the dense air systemis claimed in the presentapplication and accordingly ancillary details of such system are omittedFor example, since the entire system is above atmose pheric pressure,some leakage from the system will occur, and systems of this kindconsequently include, among other auxiliaries, some means for supplyingmake-up air. Details-of this character are not illustrated because notrelated to the subject of the present invention, but the necessity forthem is recognized and various types are available from the prior art. I

' As is well known, Diesel engines and internal combustion enginesgenerally, are limited 'in their speed range under load and are notreadily reversible. The purpose of the pneumatic M transmission is toprovide a flexible and reversible drive, which will transmit powerwithminimum losses, and which is particularly adaptable for larger powers,and applicable to boats and other propelled devices. 1 I

The present invention also provides meansto permit operation for shortperiods under overload conditions. p

Generally stated, the power plant includes a Diesel engine, preferably amultipl cylinder engine of the air injection type, with fuel feedingpumps oi the variable feed type. These pumps (0]. 19)' are not directlycontrolled by a governor, the primary control being manual. There is,however,

a governor which acts to limit over speed and which is progressivelyloadedbythe manual adjusting device so'that the governors responseeaconforms'at least approximately to the setting;

of the manual devic The pneumatic transmission fundamentally consists ofa compressor and an air motor. The

compressor may conveniently be 'a single doublees acting cylinder builtas a unit with the Diesel engine. The air motor is provided with avariable cut off valve gear and withan'unloading gear which permitsthe'air line tobe short-circuited at those times 'in'which theDiesel-engineis. in

operation and the air motor is at rest. Theair motor shouldbe-self-starting and a'convenient way of accomplishing this is touse'two double acting cylinders with cranks at The invention isapplicable to various installations,-such as locomotives, ships and thelike, but will be described asa pplied to atow-boat of the stern paddlewheel type? For this purpose it is convenient to use a distributinggear-of the drop out 01f type, and an unloading-gear which merely 80"holds the'inlet and exhaust'valves of the cylinders open independentlyof the action of the distributing gear. When these valves are. held opena free circulatory path is afiorded through i the air motor cylinderswhile the air motorsareat rest. Y

The purpose of the present invention is to.

produce a single controller which will act simul taneously on theDieselengine and on the air motor to give complete-maneuvering rest tofull speed in either direction.

'To permit the description of the device to be understood as itproceeds, a brief statement of the control characteristics will'begiven.

With the air motors 'at rest,the Diesel engine will be operating at itsminimum speed. The

governor will be acting merely as an overspeed device and the inlet andexhaust valves of the air motor will be held open and the air pumpfwillbe circulating air in a closed path, there being lit-- tle 'difierencein pressure between the low and high pressure lines. As the actuator isshifted "ahead or astern from the stop position, itop erates aservo-motor-to set 'the valve" gear for forward or reverse direction,and in the low speed positions the air motor valve gear 'is setfor'maximumcut off. Thus in low speed positions the f compressor isbeing driven at. low speed and the air motor is operating at a longcutoff so that its air consumption is large and a relatively low n icontrol from: 90

pressure differential builds up between .high

pressure and low pressure air lines.

Thus the air engine starts slowly, but as the controller is moved towardhalf speed position,

the Diesel engine is gradually speeded up and the cut off of the anengine isgradually shortened so that bythe time half speed is reached,and

f preferably somewhat before to full speed, and the increase of speedinthe air engine from half to full speed' is secured solely by speeding upthe Diesel engine. I 7

To meet temporaryoverload conditions, it is possible to speed the Dieselengine up still further, but in order to use its power outputeffectively, it is desirable slightly 'to lengthen the cut off of theair. engine and this is done so that as the controller is moved fromfull speed position forward to its limiting overload position the fuelfeed to the Diesel engine is increased and'the cut off of the air engineis progressively lengthcried a moderate amount. -1

An embodiment. of the invention illustrating the-above parts will now bedescribed in connection with the acompanying drawings, in which,-

Fig. 1 is a plan View of. atow-boat, partly broken away showing theposition of the Diesel engine with its compressor, the position of theair motors and the main piping connections. 1

V the outline of the tow boat a gine, the

Fig.3 is averticalelevation of the Diesel engine and compressor and'ofthe control mechanism from the pilothouse to the power plant,- beingshown to ;indicate the position ofthese parts.

Figs. 3 and 4 arecomplementary views of the control meehanism',r-the twoviews being drawn tothe same scale so that when joined on the line theygive substantially the complete layout. These views are to a certainextent diagrammatic. For-example, instead of showing'theenfuel feed pumpand'its controlling mechanisin including the governor are shown.

Fig; 5 is a section on the line 5-5 of Fig. 4. Fig. dis a perspectiveview of the, controlling mechanismshown in FigsB and 4, with theexception of those-parts whichare associated di rectly with the Dieselengine. In this view sup porting bearings are ,omitted, to avoidconfusion.

Referring first particularly to Figs, land 2,

the hull nfa tow-boat is represented in outline at 11,'the deck house at12 and the pilot house at 13. The usual stern paddle wheel is indicatedber to or through which the power of thejplant at 14; This is intendedto. be typical of any memmight be applied, it being the element which isdriven at variable speed under load and which may be driven in reversedirections under the above stated conditions.

' A Diesel engine is indicated generally by the numeral 15. ,It may-beof any type, but in the example illustrated,'it is assumed to be of theair injection, two cycle type, havingfive single acting cylinders. Theupper portions of these cylinders are indicated at 16', and each has theusual fuel-injecting nozzle and valve, indicated generally at 17. v

A three stage compressor for furnishing the in jection air forms a shownat 18. The

part of suchan engine and is fuel feed pump appears at 19,

and, as is common with such engines,;is of the adjustable-feedtype-having fivcfuelfeeding it. is reached, the air each other, but tosimplify the manifolds 23 of two double-acting air cylinders 24 24 Thesecylinders are counterparts of explanation, will be one for each of thecylinders 16. Each piped to corresponding fuel injecting distinguishedbythe subscripts ,p and s indicating port and starboard respectively. Thetwo cylinders 24 '24 haveexhaust mani- Vfolds25 which are connected bythe low pressure air. line. 26 with the suction. or intake of the pump21. Each air cylinder has the usual piston connected to piston rod 27and cross head 28.

Connecting rods 29 form driving connections to? corresponding cranks31'on the; shaft of, the

paddle wheel 14. Thev cranks 31 areset at to each: other so that the airengine is :se1f-.

starting in both directionalit. being understood that the cylinders aredouble acting. Pipe 32 which appears in Fig.1 is theexhaustpipeoi theDiesel engine. 2. v

As already suggested there is a substantial ad--v vantage in using aclosed circuit between i the pump 21 and the air motor cylinders'24, butthe present invention is directed to control and is not strictly limited.to closed circuit :operation. Some of the advantages of the-inventionat least can be secured by applying the novelcontrol to that type ofpneumatic transmission in'which the compressor draws its air from'theatmosphere and the air cylinders 24 exhausttogatmosphere. This is, ineifect, a closed .circuit.in which the return :from the air cylinders'tothe compressor 1 is at atmosphericpressure. a

Referring particularly to- Fig. 2, there is in the pilot house713 avpower controlling wheel 33; This is mounted on .a shaft 34 which isgeared, as

diagrammatically indicated inFigZ, to a hand 35 which indicates on adial 36 the position of the controlling element. The shaft "54 is gearedwith Y a one-to-one ratio, to a horizontal shaft 37 which is geared witha .one-to-one ratio :to a controller shaft 38 in the engine room.- Theshaft 38 has an'operating handle 39 and'is geared to operate ahand 41-reading on 'a dial 42. ;The legends on the dial indicate the conditionofthe control mechanism.,., In=mid-positionit indicates Stop. Readingsuccessively from opposite sides of Stop position, thereiare'indications for Half speed, Full speed; and Y Overload, either;Ahead or Astern, asthe case maybe. Dial 36 ;-bears correspondinglegends. a H

.The shaft 38 drives the main control'shaft 43 through skew gears 44,45, which appear in dotted lines in Fig. 3. This shaft carries at'90?.to each other a shortcrank 46, which controls the reversingservo-motor, hereinafter describedand a longer crank .47, which controlsthefuel feed of the Diesel engine, cut-off of the air engine, andtheunloading ,gealrp In stop position the crank 17 extends to the 7 leftin'substantially horizontal direction-and the short crank 46 extendsdownward in a substantially vertical direction. The range of movementthe-end off-crank id-is to the all forward settings. 7

For astern running the crank 47 swings through about 120counterclockwise, and it follows that in all running astern settings theend of the short crank The crank 46 is connected by a reach rod 48 witha controlling lever 49 of the reversing servomotor, and functions tocause. this servo-motor to move from one extreme position to the otheras the crank 46 passes through its verticalor stop setting. i a

' The servo-motor consists of a cylinder 51 have ing a'diiferentialpiston 52. The smaller or annular area 53 .of the differential'piston 52is constantly subject to hydraulic pressure which arrives from anysuitable source of supply, such as" an accumulator, not. shown, by wayof pipe 54, valve chamber 55 and passage 56. Pressure in chamber 57 actson the larger area of the diiferential piston 52 and is controlled bythe simultaneous adjustment of two poppet valves, namely, an inlet valve58 and an exhaust valve 59. These two valves are carried on plungerstems 61 and 62 which pass entirely through the valve casing,

so as to be balanced.

The valves 58 and 59 seat in the same direction and their stems 61 and62 are each pivoted to the lever 49. A spring 63 acts on the lever andholds both valves seated in the mid-position of the lever 49. If theupper end of the lever 49 is drawn to the left it fulcrums on itsconnec-- tion with plunger 61 and unseats the valve 59' and thusexhausts the pressure in chamber 57 so that the piston 52 moves to theright in the posi-' tion shown in Fig. 4. This is thesetting-for runningahead and persists in all positions of the crank 46 to the left of itsstop position, In the stop position both valves 58 and 59 are closed. Ifthe upper end of the lever 49 is swung to the right of the stoppositionit fulcrums on its connection with stem 62, thus holding valve 59 closedand valve 58 open. 4

Under these conditions there is pressure in the space 57 and against theannular face 53 0f the piston 52, but as the head area is much thelarger, the piston 52 moves to'the left. to its limit of motion. This isthe position for reverse running, and is the conditionwhich persistswhenever the crank 46 is to the right of its stop,position.

Referring now. to Fig. 6, .as well'as to Fig.4, the piston 52 actuates arack 64 whichmeshes with a sector gear 65 on shaft 66. Shaft 66 turns inbearings, (not shown) and carries at its opposite ends cranks 67 and 67indicating port and starboard, to distinguish identical parts related.to the port cylinder 24 and the starboard cylinder 24 To these cranksare pivoted,1respectively, guide blocks 66 and 68 which receive andguide in longitudinal reciprocation, reversing links 69 69 a There aretwo rock shafts 71, 72. The rock shaft 71 is driven through an arm 73from the port cross-head 28. The rock shaft 72 is driven through an arm74 from the starboard crosshead 28. The cranks, as already explained,are displaced 96 from each other.

The valve motions for the port cylinder 24 and for the starboardcylinder 24 are derived from respective combining links 75 75 The link75 derives its motion partly from the arm 73, through link 76 and partlythroughthe member 69 which is pinned to a slide block 77 in the slottedguide member 78 'which is mounted on shaft 72. The slotted guide member78 is merely a cross guide permitting the block 77% to 46 is to theright of the shaft arm 88 upward.

be lshifted by motion ofthecrank 671 to a point above the center of theshaft 72 or a point below I such center.

, Similarly, the motion of the link 75 is a com,

bined'motion derived partly through the link 76 It will be rememberedthat the piston 52 moves,

from one limiting position to the other and this motion carries theblocks 77 and '77 from the top to the bottom of their respective.slotted' guidemembers. I g

From the links 75 and 76 to the inlet and exhaust valves of bothcylinders, the two valve gears are identical, there being an independentgear for each end of each cylinder. gear embodies the fundamentalprinciples of that described and claimed in the patent to Emil Nodistinguishing subscripts for portzor star board, parts appear to benecessary. 1

The link 75 or 75 ,as the case'may be, is connected by links 81, 82,with bell cranks'83 and 84, the first of which handles the crank rendThe valve Grieshaber, No. 1,735,045, dated November 12,

Valves, and the second of which handles the head I end Valves. Each ofthe bell cranks 83, 84, is.

connectedby a corresponding link ,85 with the.

admission and exhaust valve mechanism for one end of the cylinder. Allof these gears are similar, hence they are similarly numbered and onlyone is described (see Fig. 5).

The link is pinned to a swinging arm, 86

which is pivoted at the point 87 upon the same' axis as thevalve liftingarm 88 which is pro-.

" vided with a latch nose 89; Pivoted at '91 on the swinging lever 86 isa latch member 92 which has a nose adapted to engage the nose 89 so thatwhen the swinging link 86 moves downward the, v

latch 92 will engage the nose 89 and swing the The latch member 92 has atail 93 which. is positioned on the axis of thefulcrum 87 and 'istripped off at various points in the stroke of the engine byreciprocating trip member 94, which will be f driven as hereinafterexplained. The

liftermember 88 has thrust connection with a plunger 95 which isconnected to-the stem of the inlet'valve 96. This valve is urged in aclosing direction by a spring 97. The swinging arin86 isfurtherconnected by a link 98 to a, rock arm 99 and, this has a thrustconnection with the plunger 101 which is connected to the stemof theexhaust-valve 102. A' spring 103 urges the exhaust valve in a closingdirection.

It will be observed-Ifthat the reciprocation the link85 opens the inletand exhaust valves in'proper timed relation and that the action of themember '94 will determinethe point of cut-j oif of the inlet valve. e

The motion for the trip member 94is derived from the arms 73 and 74,that for the portengine,

being taken from the arm 73 and that for the starboard from the arm 74.As the mechanisms are the same for the two enginesonly one will a bedescribed and differentiation between the port and starboard enginesseems unnecessary.

Thedriving connection is alink 104 pivoted to the arms 73, 74, as thecase may be, and this drives a pendant lever 105 which is pivoted on arock shaft 106. Pivoted at or near midlength of each of the arms 105 isa three-arm bell crank lever -lowest position. i V v i is, turning it ina counterclockwise direction 107. Two opposed arms oi-thi's bell crankare connected by corresponding links 108, with one arm of respectivebell cranks 103. The other arm ofeach bell crank 109' is connected 'byaSimultaneous adjustment of all four members is effected by rotating therock shaft 106. This shaft carries' fixed upon it two arins 112,on-e'for the port cylinder and the otherfor the starboard cylinder. Eacharm"112 is connected withthe third the corresponding bell crank 107 by alink 113. The shaft 106 is urged in a clock wise direction (as viewedinFigs. 4 and 6) by weight114 which is mounted on an arm 115 projecting tothe right from rock shaft 106.

' 1 The" downward limit of motion ofthe arm'115 is determined by anadjustable stop 116, and when the arm 115 is swung clockwise as far asis permitted by the stop 116, the trips 94 are set for theshortestcut-off, that is, they are in their Raising of the lever 115,that througha'slightrange, raises the members 94 and lengthens thecut-off. 7 i

As explained in the general'description of the control cycle, it isdesired to shorten the cut-off as the control device moves from Stop toor Half speed position, then leave the'cut oil? unchanged -toFull-'speedposition, and then from Full speed to QVerload to slightly l'engthe' 35-he cutoff. This function is performed by rocking lever 117- mounted on arock shaft 118 and connected by link 119 with the crank 47. Thelever-1'17 has two projectinglugs 121, 122,

on opposite sides ofits shaft 113, and each un:

in its Stop position, that is, horizontal to the vandthe lug-122 liftsthe lever 115.: The parts sired cut-oil in this setting. r

As the crank 471swings" in either direction from the Stop position;lever 117 will be moved to the right, and at, or shortly before, Halfspeed position is reach d the lever 115 will have been arrestedby thestop11'6 in the minimum cut-oft position and will have been cleared bythe' 'lug From this position onto Full speedfp osalon, in eitherdirection,'the lever 115 remains undisturbed.

Eoivver, if the crank 47 be shifted beyond Full speed position into theOverload? range, the arm il'i'willagain the levcrx115, slightlylengthening the cut-off. The lug l2 l"starts to engage lever 115 at Fullspeed position,'so' that the lengthening of the cut-off commences as theoverloadcommences, and continues progressively for the range of theOverload setting; a The lever .117 projects -downward beyond the rockshaft 118 and is connected b'y' a link123 with .01 l Jer'124 of a servoinotor which in -'posiu1on operates to unload thec'ompresby holding openthe inlet and exhaust valves --e air motors. i

.7 servo-motor includes a cylinder 125 with si n-cs1 piston 12,notunlike the piston 52. T e'annular space 127 is constantly under valvechamber 129 and passage 131; The piston 125 i connected by 2. lug 132withthe'lower' end i of the lever 1'24, which'thus serves to combine the'moti on. of the piston 126 and" the link ,123.

pressure, arriving through the pipe 128,

The lever 124 is connected at an: intermediate point with a link 133'which extends'to a valve actuating arm, 134. Thisis pinned to the stems135 and 136 of an inlet valve137 and anexhaust valve 138. A spring 139tends to'seat both valves.

If the upper end of the lever 134'ismoved to the left the lever fulcrumson the valve stem 135 and uns eats the valve 137. If it is swung to theright, the valve 137 remains seated, and the valve 138 is unseated. Ifthe admission valve 137 the valve 133 causes the piston 126 to move tothe 1 derlying the 1ever'115, When the crank 47- is are soproportioned'as to givethe maxiinuin deleft- The action orthe combininglever 124 is to cause the piston 126 to follow the motions of the link123, but in the reverse direction.

Piston 126 is connected by lug 132 and a related I link 142 with an arm143 fixed on a rock shaft 144. Fixed at opposite ends of the rock shaft144 are two-armed bellcran'ks- 1451 One arm. of each bell crank 1451sconnected by'a'link 145 with the corresponding arm of a parallel bellcrank 147; The remaining arms of the two bell cranks 145, 147, areconnected to vertical links 143. She link 148 handles the head endunloadgear. 1 I

ling" gear and another the crank end unloading T.. is 'unloadingmechanism can be best undrstood'by reference to Fig. 5. "The four gearsfor both ends of the'two cylinders are identical; The link 148 isconnected to one arm of a bell crank 149, whose other arm is connectedby a link 151 with a second bell crank 152. The first bell crank 149 hasa thirdarm'153 which, whenthe link148 is drawn upward tothe extremity ofits motion,

are unseated. A. very slight'motion of the crank 47 away fromStopfposi'tion will shift the lever 1 17, and consequently the link 123suiiiciently to render the unloading gear inoperative. it: re-

quires a slight range of motion near the Stop position to shift thelever'49 and cause theservomotor piston 52 to function to setthe valvegear for forward or rearward motion. Thisjslightmo tion is alsosufficient to cause the necessary oper-' ation of the unloading, gear.

' The above description will make clear the con struction .of thereverse mechanism; the variable cut-cit mechanism and the unloading gearmechanisni, all ofwhich are applied .to the air engine: Controlof theDiesel, engine will now bodeengages andlifts the plunger 95connected toscribed'with reference to the left handi portion of Fig. 3.,

The crank47 connected by a link 155 with an arm. 156 of a bell crank,whose other arm, 157; is connected to the fuel controllingrneans and toa loadingdevice for the speedgovernor. The

arm 156 is longer than the crank47, so that its angular movement is lessthan the angular move- 11 merit of 'thecrank. The arm157'has connectedpiston 126 to the right, but the accompanying I motion-of the unloadinggear is withoutfunction asthe'unloading-cainsare simply moved furtherand further away from-operative position. 5 With the valve gear set forrotation" in one definite direction and the unloading terminated, theoperationof the Diesel engine'and its connected pump,is to establish arelatively low differential between the pressures existing in the pipes22 and 26. At first this may be of the order of iiity pounds. Thisfollows from'thefact that 'the Diesel engine is operating at low speedand the air engines startin operation with a maxi mum cuto ii, thu'susing relatively large quantities of air; Continued motion of thecontrolling shaft '43, in the assumed, direction,' increases thefuelfeed, and at thesame timeprogressively, loads the Igovernor,thus'causing the Diesel engine to increase inspeed and powerand'todeliver more air to the high pressure line 22. This progressiveincrease in speed continues to the limit of the overload position. Upto' half speed position, orjthereabout, the lug 122"progressively lowersthe lever 115 mm the minimum cut-ofi is reachedfwhen the Weight 114rests on the step {116. At this, time the Diesel engine willnothavereached its full normalspeed, but Will be operating at say abouthalf speed, and the pressure diiierential between the pipes 22'and 26will have increased materially because thepuinp is delivering more airand the air'motor cylinders are using less air because of theshortenedcut-ofim I I I "From the point where minimum cut-off is,reached up to ffull speed'the' speedcontrol is effected merely byfurther increasing thespeed furnish air at increasing rate. Under theseconditions'the standard pressure differentialbetween the pipes 22 and 26is established and maintained. I "1 I There are occasions when it isdesirable to avail of the overload capacity of the Diesel en- 'gine'forshort periods, despite thefact that this power is not aseconomicallyapplied. I

The Diesel engine is overloaded by increasing the fuel feed, andconsequently the engine speed. 7 The air engines handle theresultingincreasedhouse. The pneumatic transmission, when prop-Z erly. designed,is slightly more efiicient than any electrical transmission yetavailable, weighs less, and gives a I more flexible control. 'Moreover,it'ismorereadily adapted to certainstandard types of apparatus, notably,tow-boats and locomotives; than is the electrical'transmission.

'Whilethe mechanism as applied to tow-boats 1 haslbeen described inconsiderable detail, it is obvious that other installations will require'modificatio'nsfbut these can be-made within the scope of the presentinvention. For'example, there is a wide'range of selection in valvegears,'to permit both reversal and variable cut-off; There arecompressor'can'be unloaded, though itappearsto of the Diesel enginathuscausing the'pump to of forward and reverse running, from the pilot'various specifically different ways in which the be simplest to unloadit by shOrt-ciicuiting the air" flow through the air. motors, It isobvious, however, that any, unloadingv gear m ig'ht be operated by the pston 126, or some equivalent mechanism.

The invention is. applicable in certain .ofits features to difierent fuel feeds designed to meet the requirements of 'partic'ularfcases.(Furthermore, I have illustrated a strijctly"mechanical connection asthe remote pilot house control. However, various remote.controlmechanisms are known; some of which are not strictly mechanical,and I contemplatethe use of any controller capable of application so,that the. motion of a handle or the like, at a control station, willproduce a similar motion of a controller in the engine I room, or otherproper location. In other words, th description is intended to beexplanatory, and not limiting, thescope of the invention being expressedin the claims.

What is claimed is,'

1, The method of varylng the speed and power output of a powerplant ofthe type including a' variable cut-ofi expansible chamber motorconnected in a closed circuit with a compressor which is driven atvariable speed by aprime mover; which consists in changing thejspeed ofthe'prime mover and compressor and simultaneously varying inversely thelength Ofcut-ofi of theexpansible chamber motor throughthe low'er' speedranges; and in the higher speed ranges maintaining the cut-off ofthe'expansible chamber motor at substantially the minimum value'andlvarying the speed of the prime mover and compressor; I I j 2. The methodof varying the speed and power output of a power plant of the typeincluding a variable cut-off expansibl'echamb'er' motor connected in aclosed circuit with a compressor which is driven at variable speed by aprime mover, which consistsfin changing the speed of the prime mover andcompressor and simultaneously varying inversely the length of cut-off ofthe expansible chamber motor through the lower speed ranges; in thehigher speed rangesmaintaining the cut-ofi of the expansibledchambermotor at substantially the minimum value and varying the speed of theprime'mover and compressor; and in overload ranges further increasingthe speed of theprime mover and compressor and simultaneously increasingthe cut-off of the expansible chamber motor.

3. The method of varying the speed and power I output of a power plantof the type including a variable cut-off expansible chambermotorconnected in. aclosed circuit with a compressor whichflis driven atvariable speed by a prime mover, which consists in changing the speed ofthe prime mover and compressor and simultaneously varying inverselyrthelength of cut-off of the expansible chamber motor through the'lowerspeed ranges; in the higher speed rangesmaintaining the cut-ofi of theexpansible'chamber motor at substantially the minimum value and varyingthe speed of the prime'mover and compressor; and stopping the expansiblechamber motor by unloading said compressor while said I prime mover isoperating at low speed. I

"4. The combination-with a power plant including a prime mover having anenergy input com troller, a compressor driven by said prime mover and anexpansible chamber motor deriving its motive fluid from saidcompressor'and having a I a variable cut-'oii mechanism, of a singleactuating i 50 means operatively connected to said energy inputcontroller'and to said variable cut-ofi mech anism. V

5. The combination with a power plant includ-v ing a prime mover havingan energy input controller, a compressor driven by 'said prime mover, anunloading mechanism for said compressor, and an expansible chamber motorderiving its motive fluid from said compressor andhaving a variablecut-off mechanism, of a single actuator operatively connected to saidenergy input controller, said unloading mechanism and said variablecut-ofi mechanism; 1 i

6. The combination with a power plant including a prime mover having anenergy input controller, a compressor driven by said prime mover, anunloading mechanism for said compressor, and an expansible. chambermotor deriving its motive fluid from said compressor and having avariable cut-off mechanism and a reversing mechanism, of a singleactuator operatively connected with said energy input controller, saidunloading mechanism, said variable cut-off mechanism, and said reversingmechanism.

'7. The combination with a power plant including a prime mover having anenergyv input controller, a compressor driven by said prime mover, andan expansible chamber motor deriving its motive fluid from saidcompressor and having a variable cut-off mechanism, of a single actuatoroperatively connected with said energy input con troller and variablecut-off mechanism, said actuator operating to increase the energy inputpro- 'gressively when moved from a stop position to full speed positionand serving simultaneously to shorten the cut-off progressively to abouthalf speed position, and thereafter to maintain the cut-offsubstantially constant to full speed position.

8. The combination with a power plant including a prime mover having anenergy iuput controller, a compressor driven by said prime mover, anunloading mechanism forsaid oompressor, and an expansible chamber motorderiving its motive fluid from said compressor and having a variablecut-off mechanism and a reversing mechanism, of a single actuatoroperatively connected with said energy input controller, unloadingmechanism, variable cutoflf mechanism and reversing. mechanism; saidcontroller having a stop position from which it is shifted for forwardor reverse running and 'in which said unloading mechanism is caused tofunction, the actuator serving to operate the reversing mechanism in oneor the other direction as it is moved in opposite direction from saidstop position, and serving when moved from stop position in eitherdirection tofprogressively shift said energy input controller togradually increase the energy input up to full speed position, and atthe same time to actuate said variable cut-off mechanism to shorten saidcut-01f to about half speed position, and thereafter to maintain thecut-01f substantially constant from half speed to full speed position.

9. A power plant comprising in combination, a Diesel engine having afuel feed controller; a compressor driven by said engine; an expansiblechamber motor connected in closed circuit with said compressor andhaving'a variable cut-off mechanism; and a single actuating meansoperatively connected to said fuel feed controller to vary the fuel feedprogressively throughout the control range, and operatively connected tosaid valve cut-off mechanism to shorten the' cut-off as the speedincreases to substantially half speed,

and fromhalf to full speeds to maintainthecuti 01f. substantiallyconstant;

10, A power plant-comprising in combination, a Diesel engine havingafuel feed controller; a compressor driven by said Diesel engine; anexpansible chamber motor connected in closed circuit with saidcompressor, and having avariable .cut off valve gear, and an unloading.m'eans arranged .to hold the inlet and exhaust valves of the expansiblechambenmotor. open simultanaously; and a single'actuator operativelyconnected -to said fuelfeed controller, said variabie 'cutoif valve gearandsaid unloading means, and

having -la-stop position in which said unloading.

means is rendered active, and a controlling range of motion in whichsaid fuel feedcontroller islactuated to increase the "fuel feed pro,-

gressivelyand in-which the valve gear is shifted to shortenthe cut-01fas the fuel feed is increased,

until substantially half speed is reached, "and from substantially halfto full speed is held at a constant setting to maintain said'cut' ofl(3011-, stant. I

11; Apower plant comprising incombination a Diesel engine having a' fuelfeed controller; a

compressor driven-by saidDiesel engine; an 'expansible chamber motorconnected in a closed circuitwithithe compressor,and having a variablecut off mechanism and areverseing mechanism; means for unloading saidcompressor; and a single actuator operatively connected with said-fuel'feed controller, said variable cut-off mechanism, said reversingmechanism and said M unloading mechanism, said controller' havinga stopposition in which said'unloading mechanism.

is caused to operate, and being movable in-reverse directions from saidstop position first to actuate said reversing mechanism and then tooperate si-" multaneously the fuel ,feed and variable cut-01f mechanismfirst to increase the fuel feed and shorten the'cut-off and thereafterfurther to increa'se the fuel feed while maintaining the cutoffsubstantially constant. Y T v 12. In a power plant, the combination of aDiesel engine'having a fuel feed controller; a

compressor driven by said engine; an expansible chamber motor connectedin closed circuit with said compressor and having a reversing mech-.'

anism and a variable cut-off mechanism; means for unloading saidcompressor; a servo-motor for operating said unloading means; aservo-motor for operating said reversing means; control valve mechanismsfor said servo-motorsj and a single actuator having a stop position andprogressive speedcontrolling positions on opposite'sides of said stopposition, said actuator being connected to actuate the valve mechanismsof said servomotors at the stop position, said actuator having a directconnection with said fuel feed controller and a lost motion connectionwith said variable cut-off mechanism.

13. The combination with a power plant including a prime mover having anenergy input controller, a compressor driven by said prime mover, and anexpansible chamber motor deriving its motive fluid from said compressorand having a variable cut-off mechanism, of a speed responsive governordrivenby said prime mover and having a lost motion connection with saidenergy input controller whereby the governor will control the primemover to limit excess speed;

a single manually actuated means normally effective to control saidenergy input controller but capable of being superseded in control bysaid governor under overspeed conditions, said actuwith the dropout-01fmechanism of said. valve gear and with said unloading means, and'havinga'stop position in which-said unloading ,means is rendered active, and aspeed controlling range ,ofmotion' in which said fuelfeed controller and,said drop cut-off gear are adjusted in'a definite relation to eachother. 15. n a power plant, the combination of a Diesel engine having a'fuel feed controller; a

compressor driven by said engine; an expansible chamber motor connectedin a closedicircuit with said compressor and having a reversing mecha--nism and a Variable drop cut-oil distributing valve mechanism;unloading means independent :01? said distributing valve mechanism for,hold- 7 ing the inlet and exhaust valves of said'expanof saidservo-motors at the stop position, and

sible chamber motor open simultaneously; a servomotor for operating saidunloading means; a servo-motor for operating said reversing mechanism;control valve mechanisms for said servomctors; and a single actuatorhaving a-stop position andprogressive, speed control positions onopposite sides of said'stop' position, said actuator being connected toactuate the valve mechanisms having connections with said fuel feedcontroller and said drop cut-off. mechanism to. control-the same in afixedrelation with each other.

16. The combination with a'power, plant of the type including a variablecutoff expansible chamber motor connected in aclosed circuitwith acompressor, and a variable speed prime gnover connected to drive saidcompressonof means for varying the speed ofthe priniemover through itsentire speed range, and associated means for controlling the ieng'th ofcut-off of the expansible chamber lnotoigsaid associated means beingoperable in the lower speed'range's of said,-

prime mover to vary-the cut-off of the expansible chamber motor ininverse'relation to the speed of the prime mover, said associated meansbeing maintained in substantially the minimum out oii position when saidspeed controlling meansjof the'prime mover is set for the higher speedranges of the'primeanover. 1

17. The combination with a power plantof the typev including a variable.cut-off expansible chamber motor connected in a closed circuit witha'compressoiyand a variaol speed prime mover connected to drive saidcompressor, of means for.

varying the speed of the prime mover through its norm'al'range, and anoverload range, and

associated means for controlling the cut-off of the expansible chambermotor, said associated means being'operable in the lower speed ranges,

of said prime mover to vary the cut-off of the expansiblechamber motorin inverse relation to the speed of the prime mover, andin'thehighernormal speed ranges being maintained in substantially minimum cutoftposition, and in'the overload ranges being operablejto increase thecut-on of the expansible chamber motor; 7 18. The combination with apower plant of the type including a variable cut-off expansible chambermotor connected in a closed circuit with a compressor, and a variablespeed prime mover connected to drive saidcompressor, of meansforcontrolling the speed of the prime mover between anidling speed and itsnormal full speed,

means operable in the idling position of' said' speed controlling meansfor unloading said compressor, and means associated with, said speedcontrolling means, and, operable in the lower speed ranges to vary saidcut-off in inverse relation to the speed or the prime mover, and in thehigher speed ranges to maintain said cut-0n: substantially atthe'minimum value.

' I RUDOLF wnv 'rzna.

